Fabrication of tellurite fiber via air-exhausting extrusion based on ceramics die

Abstract

During the preparation of tellurite fiber preforms, defects such as air bubbles and contaminated particles at the core-clad interface can significantly increase fiber loss. In this paper, we have proposed an effective method to solve these defects. Firstly, zirconia (ZrO2) ceramics were used as the die material due to their low contamination and high chemical stability, avoiding the surface reduction of TeO2 glass associated with metal-based die. Furthermore, the die was designed with an air-exhausting channel between the interface of the core and cladding glasses. The results demonstrate that the tellurite glass was well-preserved during the extrusion, and no visible particle defects were found at the core-cladding fiber interface. The fabricated fiber exhibits an optical loss as low as 0.67 dB/m at 1.31 μm, which is approximately 77 % lower than that of fibers prepared using a stainless-steel die. This air-exhausting extrusion based on ceramic die, proves to be an effective method for the fabrication of low loss tellurite fibers for mid-infrared.